paravirt: refactor struct paravirt_ops into smaller pv_*_ops

This patch refactors the paravirt_ops structure into groups of
functionally related ops:

pv_info - random info, rather than function entrypoints
pv_init_ops - functions used at boot time (some for module_init too)
pv_misc_ops - lazy mode, which didn't fit well anywhere else
pv_time_ops - time-related functions
pv_cpu_ops - various privileged instruction ops
pv_irq_ops - operations for managing interrupt state
pv_apic_ops - APIC operations
pv_mmu_ops - operations for managing pagetables

There are several motivations for this:

1. Some of these ops will be general to all x86, and some will be
   i386/x86-64 specific.  This makes it easier to share common stuff
   while allowing separate implementations where needed.

2. At the moment we must export all of paravirt_ops, but modules only
   need selected parts of it.  This allows us to export on a case by case
   basis (and also choose which export license we want to apply).

3. Functional groupings make things a bit more readable.

Struct paravirt_ops is now only used as a template to generate
patch-site identifiers, and to extract function pointers for inserting
into jmp/calls when patching.  It is only instantiated when needed.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Cc: Zach Amsden <zach@vmware.com>
Cc: Avi Kivity <avi@qumranet.com>
Cc: Anthony Liguory <aliguori@us.ibm.com>
Cc: "Glauber de Oliveira Costa" <glommer@gmail.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>

1 files changed, 61 insertions, 37 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index f01bfcd4bdee..3d3bf05dec7f 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -124,7 +124,7 @@ static void __init xen_vcpu_setup(int cpu)
 static void __init xen_banner(void)
 {
         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
-               paravirt_ops.name);
+               pv_info.name);
         printk(KERN_INFO "Hypervisor signature: %s\n", xen_start_info->magic);
 }
 
@@ -738,7 +738,7 @@ static __init void xen_pagetable_setup_start(pgd_t *base)
         pgd_t *xen_pgd = (pgd_t *)xen_start_info->pt_base;
 
         /* special set_pte for pagetable initialization */
-        paravirt_ops.set_pte = xen_set_pte_init;
+        pv_mmu_ops.set_pte = xen_set_pte_init;
 
         init_mm.pgd = base;
         /*
@@ -785,8 +785,8 @@ static __init void xen_pagetable_setup_done(pgd_t *base)
 {
         /* This will work as long as patching hasn't happened yet
            (which it hasn't) */
-        paravirt_ops.alloc_pt = xen_alloc_pt;
-        paravirt_ops.set_pte = xen_set_pte;
+        pv_mmu_ops.alloc_pt = xen_alloc_pt;
+        pv_mmu_ops.set_pte = xen_set_pte;
 
         if (!xen_feature(XENFEAT_auto_translated_physmap)) {
                 /*
@@ -833,12 +833,12 @@ void __init xen_setup_vcpu_info_placement(void)
         if (have_vcpu_info_placement) {
                 printk(KERN_INFO "Xen: using vcpu_info placement\n");
 
-                paravirt_ops.save_fl = xen_save_fl_direct;
-                paravirt_ops.restore_fl = xen_restore_fl_direct;
-                paravirt_ops.irq_disable = xen_irq_disable_direct;
-                paravirt_ops.irq_enable = xen_irq_enable_direct;
-                paravirt_ops.read_cr2 = xen_read_cr2_direct;
-                paravirt_ops.iret = xen_iret_direct;
+                pv_irq_ops.save_fl = xen_save_fl_direct;
+                pv_irq_ops.restore_fl = xen_restore_fl_direct;
+                pv_irq_ops.irq_disable = xen_irq_disable_direct;
+                pv_irq_ops.irq_enable = xen_irq_enable_direct;
+                pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
+                pv_cpu_ops.iret = xen_iret_direct;
         }
 }
 
@@ -850,8 +850,8 @@ static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
 
         start = end = reloc = NULL;
 
-#define SITE(x)                                                         \
-        case PARAVIRT_PATCH(x):                                         \
+#define SITE(op, x)                                                     \
+        case PARAVIRT_PATCH(op.x):                                      \
         if (have_vcpu_info_placement) {                                 \
                 start = (char *)xen_##x##_direct;                       \
                 end = xen_##x##_direct_end;                             \
@@ -860,10 +860,10 @@ static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
         goto patch_site
 
         switch (type) {
-                SITE(irq_enable);
-                SITE(irq_disable);
-                SITE(save_fl);
-                SITE(restore_fl);
+                SITE(pv_irq_ops, irq_enable);
+                SITE(pv_irq_ops, irq_disable);
+                SITE(pv_irq_ops, save_fl);
+                SITE(pv_irq_ops, restore_fl);
 #undef SITE
 
         patch_site:
@@ -895,26 +895,32 @@ static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
         return ret;
 }
 
-static const struct paravirt_ops xen_paravirt_ops __initdata = {
+static const struct pv_info xen_info __initdata = {
         .paravirt_enabled = 1,
         .shared_kernel_pmd = 0,
 
         .name = "Xen",
-        .banner = xen_banner,
+};
 
+static const struct pv_init_ops xen_init_ops __initdata = {
         .patch = xen_patch,
 
+        .banner = xen_banner,
         .memory_setup = xen_memory_setup,
         .arch_setup = xen_arch_setup,
-        .init_IRQ = xen_init_IRQ,
         .post_allocator_init = xen_mark_init_mm_pinned,
+};
 
+static const struct pv_time_ops xen_time_ops __initdata = {
         .time_init = xen_time_init,
+
         .set_wallclock = xen_set_wallclock,
         .get_wallclock = xen_get_wallclock,
         .get_cpu_khz = xen_cpu_khz,
         .sched_clock = xen_sched_clock,
+};
 
+static const struct pv_cpu_ops xen_cpu_ops __initdata = {
         .cpuid = xen_cpuid,
 
         .set_debugreg = xen_set_debugreg,
@@ -925,22 +931,10 @@ static const struct paravirt_ops xen_paravirt_ops __initdata = {
         .read_cr0 = native_read_cr0,
         .write_cr0 = native_write_cr0,
 
-        .read_cr2 = xen_read_cr2,
-        .write_cr2 = xen_write_cr2,
-
-        .read_cr3 = xen_read_cr3,
-        .write_cr3 = xen_write_cr3,
-
         .read_cr4 = native_read_cr4,
         .read_cr4_safe = native_read_cr4_safe,
         .write_cr4 = xen_write_cr4,
 
-        .save_fl = xen_save_fl,
-        .restore_fl = xen_restore_fl,
-        .irq_disable = xen_irq_disable,
-        .irq_enable = xen_irq_enable,
-        .safe_halt = xen_safe_halt,
-        .halt = xen_halt,
         .wbinvd = native_wbinvd,
 
         .read_msr = native_read_msr_safe,
@@ -968,7 +962,19 @@ static const struct paravirt_ops xen_paravirt_ops __initdata = {
 
         .set_iopl_mask = xen_set_iopl_mask,
         .io_delay = xen_io_delay,
+};
+
+static const struct pv_irq_ops xen_irq_ops __initdata = {
+        .init_IRQ = xen_init_IRQ,
+        .save_fl = xen_save_fl,
+        .restore_fl = xen_restore_fl,
+        .irq_disable = xen_irq_disable,
+        .irq_enable = xen_irq_enable,
+        .safe_halt = xen_safe_halt,
+        .halt = xen_halt,
+};
 
+static const struct pv_apic_ops xen_apic_ops __initdata = {
 #ifdef CONFIG_X86_LOCAL_APIC
         .apic_write = xen_apic_write,
         .apic_write_atomic = xen_apic_write,
@@ -977,6 +983,17 @@ static const struct paravirt_ops xen_paravirt_ops __initdata = {
         .setup_secondary_clock = paravirt_nop,
         .startup_ipi_hook = paravirt_nop,
 #endif
+};
+
+static const struct pv_mmu_ops xen_mmu_ops __initdata = {
+        .pagetable_setup_start = xen_pagetable_setup_start,
+        .pagetable_setup_done = xen_pagetable_setup_done,
+
+        .read_cr2 = xen_read_cr2,
+        .write_cr2 = xen_write_cr2,
+
+        .read_cr3 = xen_read_cr3,
+        .write_cr3 = xen_write_cr3,
 
         .flush_tlb_user = xen_flush_tlb,
         .flush_tlb_kernel = xen_flush_tlb,
@@ -986,9 +1003,6 @@ static const struct paravirt_ops xen_paravirt_ops __initdata = {
         .pte_update = paravirt_nop,
         .pte_update_defer = paravirt_nop,
 
-        .pagetable_setup_start = xen_pagetable_setup_start,
-        .pagetable_setup_done = xen_pagetable_setup_done,
-
         .alloc_pt = xen_alloc_pt_init,
         .release_pt = xen_release_pt,
         .alloc_pd = paravirt_nop,
@@ -1023,7 +1037,9 @@ static const struct paravirt_ops xen_paravirt_ops __initdata = {
         .activate_mm = xen_activate_mm,
         .dup_mmap = xen_dup_mmap,
         .exit_mmap = xen_exit_mmap,
+};
 
+static const struct pv_misc_ops xen_misc_ops __initdata = {
         .set_lazy_mode = xen_set_lazy_mode,
 };
 
@@ -1091,7 +1107,15 @@ asmlinkage void __init xen_start_kernel(void)
         BUG_ON(memcmp(xen_start_info->magic, "xen-3.0", 7) != 0);
 
         /* Install Xen paravirt ops */
-        paravirt_ops = xen_paravirt_ops;
+        pv_info = xen_info;
+        pv_init_ops = xen_init_ops;
+        pv_time_ops = xen_time_ops;
+        pv_cpu_ops = xen_cpu_ops;
+        pv_irq_ops = xen_irq_ops;
+        pv_apic_ops = xen_apic_ops;
+        pv_mmu_ops = xen_mmu_ops;
+        pv_misc_ops = xen_misc_ops;
+
         machine_ops = xen_machine_ops;
 
 #ifdef CONFIG_SMP
@@ -1124,9 +1148,9 @@ asmlinkage void __init xen_start_kernel(void)
         xen_setup_vcpu_info_placement();
 #endif
 
-        paravirt_ops.kernel_rpl = 1;
+        pv_info.kernel_rpl = 1;
         if (xen_feature(XENFEAT_supervisor_mode_kernel))
-                paravirt_ops.kernel_rpl = 0;
+                pv_info.kernel_rpl = 0;
 
         /* set the limit of our address space */
         reserve_top_address(-HYPERVISOR_VIRT_START + 2 * PAGE_SIZE);